Determination of the Weighted Computed Tomography Dose Index in Coronary Multidetector Computed Tomography Angiography

Document Type : Original Article (s)

Authors

1 Professor, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 MSc Student, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 Assistant Professor, Department of Cardiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

4 PhD Student, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Multislice computed tomography (CT) angiography is a robust imaging method for noninvasive assessment of coronary artery diseases, which is associated with high radiation dose. Having knowledge of the various parameters used to estimate the dose plays an important role in increasing the understanding of dose delivered to patients and help operators and technologist to reduce the dose. In this research, the amounts of Weighted Computed Tomography Dose Index (CTDIW) for coronary CT angiography exams were measured in Isfahan city, Iran.Methods: To calculate the dose, an ionization chamber (Piranha, X-ray Analyzer, RTI Electronics and Sweden) and acrylic body phantom were used. Common conditions of coronary CT angiography used in two centers were applied for this project. Finally, CTDIW of all the scans were calculated using the related formulation.Findings: The amount of mean CTDIW for calcium score exams in Sina and Alzahra hospitals were 0.468 ± 0.190 and 2.354 ± 0.610 mGy, respectively (P = 0.007); and for coronary CT angiography scans in Sina and Alzahra hospitals were 6.221 ± 1.290 and 5.299 ± 0.840 mGy, respectively (P = 0.860).Conclusion: CTDIW for the calcium score was significantly different in the two centers, but there was not significant difference in the two centers for coronary CT angiography scans. In this study, the amount of CTDIW was much lower than the measured in other centers. Since scan parameters have an important effect on the dose value, training and precision of technologist result in dose reduction and patient radiation protection.

Keywords

References

  1. Afzalipour R, Mahdavi S, Khosravi H, Neshasteh-Riz A, Fatemeh Hosseini A. Evaluation of diagnostic reference dose levels in CT- scan examinations of adolescence in Tehran: a brief report. Tehran Univ Med J 2013; 71(2): 122-7. [In Persian].
  2. Sabarudin A, Sun Z. Radiation dose measurements in coronary CT angiography. World J Cardiol 2013; 5(12): 459-64.
  3. Tavakoli MB, Heydari K, Jafari S. Evaluation of diagnostic reference levels for CT scan in Isfahan. Global Journal of Medicine Researches and Studies 2014; 1(4): 130-4.
  4. Tavakoli HM, Jabari K, Salman J. SU-E-I-51: Investigation of absorbed dose to the skin, eyes and thyroid of patients during CT angiography and comparison with conventional angiography. Med Phys 2012; 39(6): 3636.
  5. Morin RL, Gerber TC, McCollough CH. Radiation dose in computed tomography of the heart. Circulation 2003; 107(6): 917-22.
  6. Earls JP, Berman EL, Urban BA, Curry CA, Lane JL, Jennings RS, et al. Prospectively gated transverse coronary CT angiography versus retrospectively gated helical technique: improved image quality and reduced radiation dose. Radiology 2008; 246(3): 742-53.
  7. Burrill J, Dabbagh Z, Gollub F, Hamady M. Multidetector computed tomographic angiography of the cardiovascular system. Postgrad Med J 2007; 83(985): 698-704.
  8. Greffier J, Macri F, Larbi A, Fernandez A, Khasanova E, Pereira F, et al. Dose reduction with iterative reconstruction: Optimization of CT protocols in clinical practice. Diagn Interv Imaging 2015; 96(5): 477-86.
  9. Najafi M, Deevband MR, Ahmadi M, Kardan MR. Establishment of diagnostic reference levels for common multi-detector computed tomography examinations in Iran. Australas Phys Eng Sci Med 2015; 38(4): 603-9.
  10. Gorycki T, Lasek I, Kaminski K, Studniarek M. Evaluation of radiation doses delivered in different chest CT protocols. Pol J Radiol 2014; 79: 1-5.
  11. Shahbazi-Gahrouei D, Baradaran-Ghahfarokhi M. Assessment of entrance surface dose and health risk from common radiology examinations in Iran. Radiat Prot Dosimetry 2013; 154(3): 308-13.
  12. Dixon R, Anderson J, Bakalyar D, Boedeker K, Boone J, Cody D, et al. Comprehensive methodology for the evaluation of radiation dose in x-ray computed tomography. Report of AAPM Task Group: The Future of CT Dosimetry. College Park, MD: American Association of Physicists in Medicine; 2010.
  13. Bouzarjomehri F, Zare MH, Shahbazi D. Conventional and spiral CT dose indices in Yazd general hospitals, Iran. Iran J Radiat Res 2006; 3(4): 183-9.
  14. Saravanakumar A, Vaideki K, Govindarajan K N, Jayakumar S. Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India. J Med Phys 2014; 39(1): 50-5.
  15. Janbabanezhad TA, Shabestani-Monfared A, Deevband MR, Abdi R, Nabahati M. Dose assessment in computed tomography examination and establishment of local diagnostic reference levels in Mazandaran, Iran. J Biomed Phys Eng 2015; 5(4): 177-84.
  16. Tsapaki V, Rehani M. Dose management in CT facility. Biomed Imaging Interv J 2007; 3(2): e43.
  17. Treier R, Aroua A, Verdun FR, Samara E, Stuessi A, Trueb PR. Patient doses in CT examinations in Switzerland: implementation of national diagnostic reference levels. Radiat Prot Dosimetry 2010; 142(2-4): 244-54.
  18. Schoepf UJ. CT of the Heart: principles and applications. New York, NY: Springer Science and Business Media; 2007.
Journal of Isfahan Medical School
Volume 34, Issue 398 - Serial Number 398
July and August 2016
Pages 1060-1065

Files

History

  • Receive Date: 10 July 2016
  • Revise Date: 01 November 2024
  • Accept Date: 06 April 2022

Share

How to cite

Statistics